Revived Afghan peace talks hit their first roadblock on Wednesday, a day after they were announced, as Afghan President Hamid Karzai said his government would not join U.S. talks with the Taliban and would halt negotiations with Washington on a post-2014 troop pact. The United States and the Taliban had announced on Tuesday that officials from both sides will meet in Doha, the capital of Qatar, in coming days, in a step forward for a stuttering peace process after 12 years of bloody and costly war between U.S.-led forces and the insurgents. But the precise timing of the negotiations was uncertain on Wednesday as U.S. officials worked furiously to keep the nascent peace talks on track. Officials of Karzai's government, angered by the opening of a Taliban political office in Doha on Tuesday, said the United States had violated assurances it would not give official status to the insurgents. "As long as the peace process is not Afghan-led, the High Peace Council will not par